Vehicle control with manual back up

ABSTRACT

A manual control means for electrically driven and controlled steering, and/or accelerating and/or decelerating of a road vehicle, comprises a hand grip means, sensors for sensing a force and/or a movement imposed on the hand grip means which correspond to a desired steering direction, and/or acceleration and/or deceleration of the vehicle, as well as a manual lever means comprising at least one mechanical connection for mechanically steering, and/or accelerating, and/or decelerating (e.g. maintenance parking etc.) of the vehicle in the absence of electric power, e.g. in the case of an electric power failure or in the case of electric power switched off, maintenance, garage parking etc., said manual lever means being swivable or rotatable about at least one axis for actuating said at least one mechanical connection.

[0001] The invention is related to the field of manual control means for electrically driven steering and/or decelerating and/or accelerating of a road vehicle. Such control of vehicles is becoming more important as a result of recent developments related to electromechanical actuators. e.g. screw actuators for driving the vehicle brakes, steering column, clutch etc.

[0002] The purely mechanical control of standard brakes etc. relies on mechanical or hydraulic links, such as the hydraulic piping in the case of braes, the rotating steering column. Also the flexible cable or lever drive connected to the accelerator pedal, are well known.

[0003] It is envisaged however, that the full benefits of electrically steeling devices etc. will be obtained in case also the manual control means are adapted to the electric character thereof. This would enable to select a more flexible design of e.g. the routing of the command links through the vehicle, and would also save costs. On the other hand, the overall safety level of the vehicle should not be impaired, in particular having regard to possible electric power interruption.

[0004] The object of the invention is therefore to provide a manual control means which is specifically adapted to the electric character of recent steering, braking, accelerating devices etc., and which also can ensure the required safety level.

[0005] This object is achieved by the invention in that a manual control means is provided for the electrically driven and controlled steering and/or accelerating and/or decelerating of a road vehicle, comprising a hand grip means, sensors for sensing a force and/or a movement imposed on the hand grip means which correspond to a desired steering direction, and/or acceleration and/or deceleration of the vehicle, and manual lever means comprising at least one mechanical connection for mechanically steering, and/or accelerating, and/or decelerating of the vehicle in the absence of electric power, such as in the case of an electric power failure or in the case of electric power switched off, maintenance, garage parking etc., said manual lever means being rotatable about at least one axis for actuating said at least one mechanical connection.

[0006] The manual control means according to the invention comprises first of all a hand grip means which is influenced by the human hand so as to provide the desired steering, and/or decelerating and/or accelerating signals. These signals can be conveyed to the respective electromechanical actuator devices through electric cables, which enables a flexible muting. Additionally, the manual control means comprise a mechanical back-up device for each function, which makes it possible to achieve a safe conduct of the vehicle in the case of a power interruption. This can be the case in an emergency situation, but the mechanical back-up system can also be used in other circumstances, e.g. during maintenance, garage parking etc.

[0007] During mechanical control of the vehicle, the control forces to be exerted on the hand grip means should of course a limited for the driver so as to maintain control over the vehicle Preferably therefore, the hand grip means is at one end of the manual lever means, the other end of said manual lever means being swivable about at least one axis and comprising a mechanical connection which provides a displacement and/or a rotation upon swivelling the manual lever means about said axis.

[0008] In particular, the manual lever means is swivable about two non parallel axes and comprises two mechanical connections which each provide a displacement and/or a rotation upon swivelling the manual lever means about the corresponding axis. Such manually operated lever provides e.g. a rotating torque which is high enough for steering the vehicle, while at the same time operating forces to be exerted by the driver can remain limited.

[0009] According to a preferred embodiment, a support means is provided which caries a first swivel having a first swivel axis, a second swivel being provided on the first swivel and having a second swivel axis transverse with respect to the first swivel axis, the manual lever means being connected to the second swivel, and an immobilisation means which immobilises the manual lever means with respect to the support means in the case of nominal operation and availability of electric power, and which allows swivelling motion in the case of power failure.

[0010] During normal operation, the control of the vehicle takes fully place through the electric sensors of the hand grip means, e.g. a joystick which provide the signals required for steering, decelerating and/or accelerating. In the case of electric power failure, the hand grip means can make additional swivelling motions so as to perform these functions in a purely mechanical way.

[0011] Said immobilisation means may comprise an electromagnetic coupling.

[0012] Although reference has been made before to the control of electromechanical actuators, also electro-hydraulic actuators can be controlled by the manual control means according to the invention.

[0013] The invention will now be described further with reference to an electromechanical steering device according to the invention as shown in the drawings.

[0014]FIG. 1 shows the general layout of a vehicle provided with a manual control means for an electric steering and brake device according to the invention.

[0015]FIG. 2 shows the general layout of the electric steering device according to the invention.

[0016]FIG. 3 shows a cross-section of the screw actuator.

[0017] The vehicle shown in FIG. 1 comprises a steering actuator 1 which is connected to the front wheels of the vehicle, as well as a joystick 26 situated near the driver's seat. Furthermore, electromechanical brake actuators 28 are provided which control the disk brakes on all wheels of the vehicle, and which also may be controlled by the joystick 26. Electromechanical drum brakes may also form a part of a complete electromechanical brake system.

[0018] The joystick 26 is connected to an electronic control unit 27, which through the driving dynamic controller 29 controls the electric motor 2 of the screw actuator 1.

[0019] The joystick 26 also controls the electromechanical brake actuators 28 on the basis of signals received from the wheel speed sensors 30. Furthermore, sensors 31 have been incorporated which monitor the driving status, all sensors being connected to the sensor electronics control device 32.

[0020] As shown in FIG. 2, the control unit 27 receives signals related e.g. to the load exerted on the screw actuator 1, displacements and/or rotations of components thereof, through cable 33. Through cable 34, the control unit 27 receives signals from the joystick 26. On the basis of these signal, the electric motor 2 is controlled, through cable 35, for actuating the screw actuator 1.

[0021] The joystick 26 is mounted at the free end of the lever 23, which is rotatable around a vertical axis on the swivel point 24. Furthermore, the lever 23 can pivot about the horizontal pivot axis of the hinge 36.

[0022] By means of the immobilisation means 25, e.g. an electromagnetic coupling, the lever 23, and thereby the joystick 26 are held in a nominal position under nominal conditions, that is when electric current is available.

[0023] In the absence of electric current, e.g. when the electric current is switched off or in case of an electric power failure, the electromagnetic coupling 25 is released and by manipulating the lever 23 through the joystick 26, a rotation through swivel 24 is imparted on the flexible cable 4 which is capable to transmit a torque.

[0024] In urn, this flexible cable 4 drives the screw actuator 1 in such a way that steering action is still possible.

[0025] Additionally, a flexible brake cable 37 is provided, which, in the absence of an electric power, is controlled by pivoting the lever 23 about the hinge 36. The flexible cable 37 is connected to the brake actuators 28, bum is not shown in further detail.

[0026] The actuator applied can be executed with a rotating nut and a moving screw, or a moving nut and a rotating screw.

[0027] As shown in FIG. 3, the screw actuator 1 is accommodated in a housing 19, which is non-rotatably fixed with respect to e.g. the chassis of a vehicle. The nut 12 is immovably fixed within the housing 12. The screw 13 is rotatably and translatably. supported within the nut 12 by means of the balls 38, which engage correspondingly shaped screw threads in the nut 12 and the screw 13.

[0028] The screw actuator 1 is actuated through an electric motor 2 which two bevel pinion 39 drives a first reduction bevel gear 40 which is positioned around the screw 13. The bevel gear 40 is rotatably supported by means of bearing 41. The bevel gear 40 is integrated with a sun gear wheel 8, which engages satellite gear wheels 10. The housing 1 carries a fixed ring gear wheel 9, which also engages the satellite gear wheels 10.

[0029] The satellite gear wheels 10 are rotatably mounted on a carrier 11, which through the spline/ball mechanism 20 is able to rotate the screw 13.

[0030] The bevel gears 39,40, as well as the satellite gear wheel mechanism 8-11 provide the necessary reduction of the motor rotations for driving the screw actuator 1.

[0031] In case of an electric power interruption, the electric motor 2 is no longer able to drive the screw actuator 1. For this reason, a mechanical back-up system is provided, comprising a flexible cable 4, which is connected to electromagnetic coupling 6. In case of a power interruption 6, this electromagnetic coupling 6 connects the flexible cable 4 to the auxiliary drive (bevel) gear wheel 14. The auxilliary drive gear wheel 14 engages a bevel gear 21, which surrounds the screw 13. The bevel gear 21 is integrated with an auxilliary carrier 15, rotatably supported with respect to the housing by means of the bearing 42.

[0032] The carrier 15 carries auxiliary satellite gear wheels 16, which engage a fixed auxiliary rung gear wheel 17, as well as an auxiliary sun gear wheel 18 integrated with the carrier 11.

[0033] By rotating the flexible cable through the lever 23 (see FIG. 2) the screw 13 can thus be rotated mechanically.

[0034] The bevel gears 14, 21 or other appropriate gear transmission principles are preferably accelerating gear wheels. 

1. Manual control means for electricity driven and controlled steering, and/or accelerating and/or decelerating of a toad vehicle, comprising a hand grip means (1), sensors for sensing a force and/or a movement imposed on the hand grip mans which correspond to a desired steering direction, and/or acceleration and/or deceleration of the vehicle, and manual lever means (2), comprising at least one mechanical connection (3, 4) for mechanically steering, and/or accelerating, and/or decelerating (e.g. maintenance parking etc.) of the vehicle in the absence of electric power, e.g. in the case of an electric power failure or in the case of electric power switched of, maintenance, garage parking etc., said manual lever means (2) being swivable or rotatable about at least one axis (5, 6), characterised by an immobilisation means (10) which immobilises the manual lever means (2) with respect to the support means (7) in the case of nominal operation and availability of electric power, and which allows swivelling motion in the case of power failure.
 2. Control means according to claim 1, why the immobilisation means comprise an electromagnetic coupling (10).
 3. Control means according to claim 1 or 2, wherein the lever means (2) engage a gear reduction located at a swivel (8, 9).
 4. Control means according to any of the preceding claims wherein the handgrip means is a joystick with or without integrated pressure buttons.
 5. Control means according to any of the preceding claim, wherein a support means (7) is provided which cares a first swivel (8) having a first swivel axis (6), a second swivel (9) being provided on the first swivel (8) and having a second swivel axis (5) transverse with respect to tile first swivel axis (6), the manual lever means (2) being connected to the second swivel (9). 